问题 计算题
用简便方法计算。
(1)19.4-1.28-3.72(2)1.25×0.25×32
(3)31.7×0.9+3.17(4)2.5×4.6+0.25×46
答案

(1)19.4-1.28-3.72

 =19.4-5

 =14.4(2)1.25×0.25×32

 =1.25×8×(4×0.25)

 =10

(3)31.7×0.9+3.17

 =3.17×(9+1)

 =31.7(4)2.5×4.6+0.25×46

 =0.25×2×4.6

 =23

解答题
材料分析题